Droplet spreading on surfaces with hybrid wettability

[Muhyminul Islam]

Hello everyone,

I am new to Basilisk and interested in simulating the spreading of droplets on solid surfaces with hybrid wettability. I came across the example sessile.c, which demonstrates a liquid drop resting on a solid surface using the embedded boundary approach.

My question is: is there any existing test case (or guidance) where the embedded solid surface is assigned different wettability conditions in different regions? For clarity, I have attached an image to illustrate the type of setup I have in mind.

As a follow-up: is it possible to assign multiple contact_angle fields to different parts of the same embedded geometry (e.g., one patch hydrophilic and another hydrophobic)?

Thank you in advance for any suggestions.

Best regards,
Muhymin

[Théophile Gaichies]

Hello,

I've tried to just put a condition that makes theta vary in the contact_angle macro in the boundary conditions, for example :

h.t[left] = contact_angle((y < 0. ? theta1: theta2));
h.r[left] = contact_angle((y < 0. ? theta1 : theta2));

To create two zones of different wettability on the left side of the simulation box. It seems to work in my test simulations. However, this is just a tweak, and I can't guarantee that it won't cause problems.

Hope this works for you !

Théophile